问题 解答题
(1)化简:
x2
x-2
-
4x
x-2
+
4
x-2

(2)先化简代数式(
a+1
a-1
+
1
a2-2a+1
a
a-1
,然后选取一个你喜欢的a值代入求值.
答案

(1)原式=

x2-4x+4
x-2
=
(x-2)2
x-2
=x-2;

(2)原式=

(a+1)(a-1)+1
(a-1)2
a-1
a
=
a2
(a-1)2
a-1
a
=
a
a-1

取a=3代入,则原式=

3
3-1
=
3
2

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